Our insatiable appetite for the big picture is threatening the planet. A scientist has warned that if half of British homes buy a plasma-screen TV, two nuclear power stations would have to be built to meet the extra energy demand.

Britons were buying flat-screen TVs every 15 seconds from Currys and its online sister company Dixons during the build-up to the World Cup, and subsequent price reductions have ensured they remain hugely popular.

But plasma sets can use up to four times as much electricity as the old-style cathode-ray tube models. Combined with set-top boxes, digital video recorders, DVD players and home PCs, the digital home is seen by environmental campaigners as a growing contributor to the energy crisis.

Dr Joseph Reger, chief technology officer at Fujitsu Siemens Computers in Munich, Germany, said: 'If all the [plasma] TVs were on at the same time, you would need something that produces 2.5 gigawatts. That can be done today with around two nuclear power stations.' But Reger added: 'It is safe to assume that there will be extras because people rarely just buy a TV. They desire a better picture and all of a sudden you have the urge for the latest and greatest DVD player. Then you need more file space on your personal video recorder. You want to download movies and it all adds up.'

Once all the elements of the 'digital home' are factored in, Reger calculates, the additional power requirement at peak hours may be six gigawatts.

In the meantime, growing electricity demands are placing a strain on conventional power stations. One quarter of all carbon emissions in Britain come from energy used in the home, about the same as transport. Simply leaving devices such as TVs and DVD players on standby at home puts up to 1m tonnes of carbon a year into the atmosphere and costs each household around £25.

The government recently called 11 electronics retailers - including Argos, Amazon, Asda, Comet, the Dixons Group, John Lewis, Sainsbury's and Tesco - to a summit at 11 Downing Street to discuss cutting greenhouse gas emissions from their products. Gordon Brown's last Budget contained an initiative for retailers to sell energy-efficient goods by 2010.

Last year consumer electronics used the equivalent of 18 terawatt hours - equivalent to the annual output from five standard power stations, and amounting to 30 per cent of the country's total domestic electricity consumption. The Department for the Environment estimates this could rise to 31 terawatt hours by 2010, mainly due to the rise in the number of TVs, demand for bigger screens and set-top boxes. Projections show that more than 50 million digital set-top boxes will be in UK homes by 2012. Philip Sellwood, chief executive of the Energy Saving Trust, said: 'As the consumer electronics market continues to grow, further development of energy-efficient products will be vital to help in the fight against climate change. TVs are here to stay, but people can change how they use them, for example, turning them off standby when not in use.'

Reger remains optimistic, believing that plasma screens will be overtaken by more energy-efficient technologies. 'I think it will be a general requirement because people increasingly have an environmental conscience,' he said. 'Equipment with a sticker that says, "Extreme low standby" will be a selling point.

'It's a short-term problem, but to say it will automatically right itself is also wrong. Inefficient TVs can be around in homes for five or 10 years.'